Internal-combustion engine.



A. BOLLASON.

INTERNAL CQMBUSTION ENGINE. APPLIoATIoN FILED Amma. 1906.

PATEN'IED 00T. 15, 190'7.

WIIN ESSES PATENTEE OCT. 15, 19o? A. EoLLAsoN. INTERNAL coMEUsTIoN ENGINE.

APPEIOATION FILED 4116.28. isos.

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ARTHER RoLLAsON, oF LONG EATON, ENGLAND, ASSIGNOR To ROBERT MOND, or LONDON,

' f ENGLAND.

INTERNAL-comenten ENGINE l i.

Specification of Letters PatentA lPatented Oct. 15, 1907.

application nea August 28,1906. serai No. 332,313.

To all whom it may concern: Be it known that I, ARTHUR RoLLAsoN, a subject of the I {ing of Great Britain and Ireland, residing at Long Eaton, in the county of Derby, England, engineer, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

.This invention relates to single cylinder internal combustion engines working on the ourstroke cycle, and hasfor its object to increase the economy and eciency o1' such engines and to prevent or reduce shock and avoid strains which arise in operating.

With this object in vview a double or differential piston is employed one part constituting the working pist0n and the other a pump piston reciprocating -synchronously with the working piston in an extension ofy the workingcylinder, and the admission valve, the gasl and mixing valve, and the air valve are made separate and are mechanically operated in such a manner that .I

'A and l the working piston., (l the pump cylinder und 1' during the suction stroke astratified charge is taken into the cylinder, 'first' air, then gas, and finally air, as

described in a prior application filed by the present h applicant on 26th September 1905,' the Serial No. of which is 280115. v

In the present invention the air and admission valves remain open until the piston begins to return on the compression stroke, the velocity of the air through the valves being utilized to increase the mass of the charge taken into the cylinder and raise the pressure there-ol as much as possible before direct (,mupression conlmences. l

These and other features constituting the present invention will be more speci ically described with reference to thcl accompanying drawings in which Figure l shows a longitudinal section of the improved4 engine. Fig. 2 is a section through the air inlet valve, Fig. 3 is a section through the mixing valve, Fig. 4 is a diagram showing the relative periods at (which the various valves open and close during one complete cycle.

Referring to the drawing, C is the working eylindcl the pump piston. l

.A is a p Ort communicating with the atmosphere and controlled by a slide valve vD which is pera-ted by a cam H on a longitudinal' lay shalt M and is held open for fully three strokes of thc engine cycle to allow the air to be freely drawn and expelled by the pump pistonA (onnnunication between the working cylinderand the atmosphere is establisluul throughthe inlet valve I, ports in the 'valve J, passage li, slide valve l) and port A. 'lhe vulve .l controls the admission olthe air and gas into the cylinder on the suction stroke and forms a mixing or diffusing valve when opened, and when closed and in the normal position shown in the drawing allows free access of air for scavenging. l

' E is .the exhaust valve admitting to an exhaust chamber E the Walls of which are exposed to the cooling Water which enters at F traverses the exhaust jacket F andpasses thence around the water jacket G of the working cylinder to the discharge outlet G.

When the suction stroke begins, the clearance space in rear ofthe piston P is filled with air and as both the inlet and exhaust valves I, E, are at the moment open, the air is at atmospheric pressure.

rspindle J is now depressed by the action oi a second cani Non the lay shaft, taking with it the valve J which cuts off the entrance of air through the valve ports, the

gas ports K which communicate with the space K being at the same time uncovered, thus admitting gas only to the cylinder. When near the end of the suction stroke according to the quality of the gas .the valve J is raised and air only is taken into the cylinder, being drawn through the slide valve D, which is now open, passage and ports in valve J' and inlet valve l. The valvesl, J and l) remain open until the piston begins te return on the compression stroke, by which time,.

since the flow oi the entering gases has been at n high velocity, the air taken in last will by reason ol' its inertia have crowded into the cylinderso as to raise the pres- The-gas valve tion products are being exp lled from the working cylinder ol' the piston P. Just before the end of the exhaust stroke that isv to say when about /lOths ol' the stroke has been completed thc valve l is opened and the air stored under pressure in the passages l5, l sweeps out the remaining products of combustion and leaves cool air in the clearance behind the piston l, as stated to be the condition at the beginning of the cycle.

Fig. l shows diagranunatically the periods at which the opening and closing of the various valves, as alluded I to above, occur, and the relative setting ol' the cams on the lay shaft can easily be deduced therefrom. lho expansion stroke, or the commencement of the cycle, is represented as beginning at Q and the end of the com. pression stroke, or the end of the cycle, occurs at Q. The exhaust valve E opens at lt and closes at H: the air slide valve l) opens at 'l and remaining open duringr the suction, compression, and expansion strokes, closes at V dnring'the exhaust sti-bke; th(l :ulmissinn vulve l opens at V :ind cluses :it W; the gas ports open :it X :nid close at Y; und ignitun of the charge occurs nt Z.

Having thus described thc nzilurr of 1n v sal-id invention and the lwstlinezi-ns l know nl' carrying thc suine inte pray-tical effect. I duim:-

A sing-le cylinder four stroke cycle internal combustion engine b:l\'in,'r n scavenging; piston recprcnted by the pismn rofl af the engine, :in nil' vulve controllingv the admis 'cycle :1nd closed to cut oli.' corunnmieation with the ni'- mosphere only during the exhaust stroke. :i rumbined uns :influir cmn'rni valve, said nir control vulve beingl inter posed between the nil' admission -vulve :md the cylinder inlet` vulve and beim: open dni-in.:A the entire cycle except for nportion of the suction stroke. duringr which the :rus vulve is upon. substantially :is described.

ln testimony whereof I have signed my nume to this specification in the presence of two subscribing witnesses.

\ ARTHUR ROLLASON Witnesses 

